{ "id": "1208.2184", "version": "v2", "published": "2012-08-10T14:18:02.000Z", "updated": "2014-07-09T23:41:59.000Z", "title": "The realizability of operations on homotopy groups concentrated in two degrees", "authors": [ "Hans-Joachim Baues", "Martin Frankland" ], "comment": "Version 2: Some minor corrections. A few changes to the exposition. To appear in the Journal of Homotopy and Related Structures", "doi": "10.1007/s40062-014-0086-3", "categories": [ "math.AT" ], "abstract": "The homotopy groups of a space are endowed with homotopy operations which define the \\Pi-algebra of the space. An Eilenberg-MacLane space is the realization of a \\Pi-algebra concentrated in one degree. In this paper, we provide necessary and sufficient conditions for the realizability of a \\Pi-algebra concentrated in two degrees. We then specialize to the stable case, and list infinite families of such \\Pi-algebras that are not realizable.", "revisions": [ { "version": "v2", "updated": "2014-07-09T23:41:59.000Z" } ], "analyses": { "subjects": [ "55Q35", "55Q40", "55Q45", "55Q15", "55P20" ], "keywords": [ "homotopy groups", "realizability", "list infinite families", "sufficient conditions", "eilenberg-maclane space" ], "tags": [ "journal article" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2012arXiv1208.2184B" } } }